Electrically conductive emulsions



United States Patent 3,027,333 ELECTRICALLY CONDUCTIVE EMULSIONS NathanH. Friedman, Stratford, Conn., assignor to Burton Parsons Chemicals,Inc., Washington, D.C., a corporation of Delaware No Drawing. Filed Dec.30, 1957, Ser. No. 705,820 7 Claims. (Cl. 252-521) The present inventionrelates to electrically conductive systems, and particularly to a newand improved system for use with electrodes in making cardiograms.

Diiferent parts of the surface of the body have different resistances tothe passage of electric current. Some skin may be dry and thick, whereasother skin may be moist and thin. Still other skin may be oily, and thedegree of hair on skin varies widely. All of these skin characteristicsact to vary the passage of electric current from the body of a patientto electrocardiographic equipment thereby providing erratic tracings.

The principal object of this invention is to provide a system that willact to enhance the passage of electric current between the body of apatient and electrocardiographic equipment. 1

Another object of this invention is to provide such a system that willbe readily applied and readily removed without any resulting conditionrequiring cleansing.

Another object of the invention is to provide such a system that willnot only cleanse the skin, but will provide high conductivity betweenthe skin and electrocardiographic electrodes.

Another object of the invention is to provide such a system in which,when applied to the body of a patient, contact dermatitis is lessenedwhile increased conductivity is provided.

Another object of this invention is to provide such a system in whichthe growth of bacteria, molds or yeast is inhibited.

One aspect of this invention may be to provide an aqueous system thatmay include a base of emulsified material of an anionic, cationic,non-ionic or amphoteric type.

Another aspect of the invention may be to include with said base, anysalt suitable to act as a conductor for the passage of electric currentfrom an electrode to the body of a patient.

Still another aspect of the invention may be to employ a bufier solutionwith the system in order to provide the degree of acidity correspondingsubstantially to the acid mantle of the body skin.

Finally, inhibitors for preventing the growth of bacteria, molds oryeast may be included, although such inhibitors may be dispensed with ifthe system is packaged in a pressure dispensing container of the typecommonly known as aerosol packages.

The above as well as other objects and novel features of the inventionwill become apparent from the following specification.

The base of the system forming this invention may comprise an aqueoussystem of an emuslified material which may be of an anionic, cationic,non-ionic or amphoteric type. Such non-ionic materials may be selectedfrom the group including polyglycol fatty acids, Spans and Tweens andthe like.

Span is the registered trademark of the Atlas Powder Company for aseries of non-ionic surface active agents which are long chain fattyacid partial esters of hexitol anhydrides, including sorbitans,sorbides, mannitans, and mannides.

Tween is the registered trademark of the Atlas Powder Company for aseries of non-ionic surface active agents which are polyoxy alkylenederivatives of hexitol anhydride partial long chain fatty acid esters.

3,027,333 Patented Mar. 27, 1962 "ice Percent Sodium chloride l-lOPotassium chloride l-l0 Sodium sulf e 1-10 or any highly ionizable saltin concentrations to achieve suitable conductivities.

Although the aqueous system of an emulsified material and a highlyionizable salt may be employed alone, should it be desired to produce apH in the system that will correspond substantially to the acid mantleof the bodily skin, any one of many buifer solutions may be utilized,among which may be included a sodium citrate, a citric acid, or aphosphate buffer solution. The amount of bufier solution employed shouldbe such as to produce a pH of between substantially 4.2 to 6.

Should the system be packaged in containers that are opened to theatmosphere during use, means may be required to prevent the growth ofbacteria, molds or yeast. Such materials as esters of para-hydroxybenzoic acid or other suitable inhibitors may be employed. Should,however, the aqueous system be packaged in a pressure dispensingcontainer of the type known as aerosol packages, the above inhibitorsmay not be required.

Examples of an aqueous system embodying the principles of thisinvention'are:

Non-ionic: Percentage Sodium nitrite 0.1 Non-ionic blend of ethyleneoxide derivatives of lanolin-higher fatty alcohols 6.0 Cetyl alcohol 2.0Sodium chloride 5.0 Glycerin 5.0 pH 5 Bufier solution 81.9

0f. T. C. MacIlvaine, Journal of Biol. Chem. 49, 183

(1921) C. J. Schollenberger, The Chemist-Analysist, 19, No.

Cationic:

Methylene bis-stearmide 10.0 Stearyl polyoxyethylamine 1.7 Glacialacetic acid 0.3 Sodium nitrit 0.1 Sodium chloride 5 .0 Glycerin 5.0 pH 5Butler solution 77.9 Anionic:

Sodium lauryl sulfate 1.0 Glyceryl monostearate (free from soap) 11.0Cetyl alcohol 1.0 Sodium nitrite 0.1 Sodium chloride 5.0 Glycerin 5.0Water, distilled or de-ionized 76.9

Dispersion:

Magnesium aluminum silicate 3.5 Sodium chloride 5.0 pH 5 Buffer solution91.5

Cf. '1. C. Macllvaine, Journal of Biol. Chem. 49, 183 (1921) C. J.Schollenberger, The Chemist-Analysist, 19, No. 3, 8 (1930).

The above systems were packaged by introducing 142 grams of each intosix-ounce containers which were then pressurized to about p.s.i. withnitrogen.

Although the various features of the new and improved electricallyconductive system have been described in detail to fully discloseseveral embodiments of the invention, it will be evident that numerouschanges may be made in such details and certain features may be usedwithout others without departing from the principles of the invention.

What is claimed is:

1. An electrically conductive stable emulsion for use with body contactelectrodes of electrocardiograph equipment consisting essentially ofwater as a dispersion me dium, from about 3.5 to 11% of methylene bisstearamide in combination With about 1.0 to 1.7% of stearylpolyoxyethylamine as a liquid dispersion phase, from about 1 to 10% of ahighly ionizable salt for controlling the electrical conductivity of theemulsion, said salt being a member selected from the group consisting ofsodium chloride, potassium chloride and sodium sulfate, and a bulfersolution in sufiicient amount to provide'an overall composition-pH ofabout that of the acid mantle of the skin.

2. The electrically conductive composition of claim 1 wherein the highlyionizable salt is sodium chloride.

3. The electrically conductive composition of claim 1 in which theoverall pH is 4.2 to 6.

4. An electrically conductive stable emulsion for use with body contactelectrodes of electrocardiograph equipment consisting essentially ofwater as a dispersion medium, from about 3.5 to 11% of glycerylmonostearate in combination with about 1.0 to 1.7% of sodium laurylsulfate as a liquid dispersion phase, from about 1 to 10% of a highlyionizable salt for controlling the electrical conductivity of theemulsion, said salt being a member selected from the group'consisting ofsodium chloride, potassium chloride and'sodium sulfate, and a buffersolution in sufiicient amount to provide an overall composition 3 pH ofabout that of the acid mantle of. the skin.

5. The electrically conductive composition of claim 4 wherein the highlyionizable salt is sodium chloride.

6. The electrically conductive composition of claim 4 in which theoverall pH is 4.2 to 6.

7. In a method of making electrocardiograms utilizing skin contactelectrodes, the improvement comprising ap plying between the electrodesand the skin an electrically conductive stable emulsion consistingessentially of water as a disperion medium, from about 3.5 to 11% of anemulsifiable water immiscible material in combination with about 1.0 to1.7% of an emulsifying agent as the liquid dispersion phase, from about1 to 10% of a highly ionizable salt for controlling the electricalconductivity of the emulsion, said salt being a member selected from thegroup-consisting of sodium chloride, potassium chloride, and sodiumsulfate, and a buffer solution in sufficient amount to provide anoverall composition pH of about that of the acid'mantle of the bodyskin.

References Cited in the file of this patent UNITED STATES PATENTS2,534,204 Mowry Dec. 12, 1950 2,555,037 Jensen May 29, 1951 OTHERREFERENCES Bennett: The Chemical Formulary, vol. IX, page 117,

vol. X, page 61, pub. by Chemical Pub. Co., Brooklyn, NY

1. AN ELECTRICALLY CONDUCTIVE STABLE EMULSION FOR USE WITH BODY CONTACTELECTRODES OF ELECTROCARDIOGRAPH EQUIPMENT CONSISTING ESSENTIALLY OFWATER AS A DISPERSION MEDIUM, FROM ABOUT 3.5 TO 11% OF METHYLENE BISSTEARAMIDE IN COMBINATION WITH ABOUT 1.0 TO 1.7% OF STEARYLPOLYOXYETHYLAMINE AS A LIQUID DISPERSION PHASE, FROM ABOUT 1 TO 10% OF AHIGHLY IONIZABLE SALT FOR CONTROLLING THE ELECTRICAL CONDUCTIVITY OF THEEMULSION, SAID SALT BEING A MEMBER SELECTED FROM THE GROUP CONSISTING OFSODIUM CHLORIDE, POTASSIUM CHLORIDE AND SODIUM SULFATE, AND A BUFFERSOLUTION IN SUFFICIENT AMOUNT TO PROVIDE AN OVERALL COMPOSITION PH TOABOUT THAT OF THE ACID MANTLE OF THE SKIN.